Design, Synthesis, Photochemical and Biological Evaluation of Novel Photoactive Molecular Switches stars

Abstract

This doctoral thesis is mainly focused on the study of new families of molecular switches based on E/Z isomerism. Specifically, it is evaluated their photophysical and photochemical properties, and how they can be tuned by slight modifications in their structure. Moreover, the off/on photoactivation of the cytotoxicity was achieved, allowing us to localize the cytotoxic action in a specific part of the body. This thesis is divided into different chapters. First, a brief introduction is presented, which deals with a short overview of the history of photochemistry, followed by the explanation of some fundamental basis about photochemistry, which will be applied throughout this thesis. In the second chapter, the most important types of molecular switches that have been developed up until now are introduced. Then, the objectives of this work (Chapter 3) are described. In Chapter 4, it is studied a new family of molecular photoswitches based on arylidene-hydantoins together with their synthesis, photochemical and photophysical studies. In Chapter 5, the study of new derivatives based on PSB-retinal is presented. Moreover, it is compared the photoswitching process of this family of switches by means of different electronic states (singlet or triplet state). In Chapter 6 it is described the synthesis, photochemical properties and cytotoxic evaluation of a novel family of photoactive molecules based on metronidazole. Finally, in Chapter 7 it is described the synthesis and study of new derivatives which belong to a new and almost unexplored family of molecular switches based on Donor and Acceptor Stenhouse Adducts (DASAs). Furthermore, a new strategy is proposed to red-shift the absorption wavelength of these new derivatives.